Blair and Bush put on a united front

At a joint news conference, Mr Bush told reporters: "We will not waver in the face of fear and intimidation."

The president said Iraq could either move to democracy or go back to "tyranny and terror".

The two leaders also stressed the "roadmap" for Middle East peace had not been abandoned.

The Washington summit follows Mr Bush's support for Israeli Prime Minister Ariel Sharon's plan to withdraw from Palestinian land in the Gaza Strip, but retain Jewish settlements built in the West Bank in defiance of international law.

We will do what it takes to win this struggle Tony Blair US warms to UN's plan Key quotes: Bush and Blair

The president underlined his backing for that plan and both he and Mr Blair insisted it did not prejudge talks on a final settlement.

"It is a good opportunity," he said. "It gives the Palestinians a chance to create a reformed, just and free government. The Palestinian leadership must rise to the challenge.

"It gives all sides a chance to reinvigorate progress on the road map."

Coalition strategy

On Iraq, Mr Bush declared: "The prime minister and I have made our choice. Iraq will be free. Iraq will be independent. Iraq will be a peaceful nation and we will not waver in the face of fear and intimidation."

He described the resistance by insurgents as "an attempted power grab by extremists and terrorists".

But he said it would fail, because the Iraqi people had "no desire to trade one tyrant for another".

Mr Blair said "getting the job done" in Iraq was the way to ensure the sacrifice of those killed had not been in vain.

He underlined the need for the United Nations to have a "central role" in moving towards the power transition and hoped there would be a new Security Council resolution over Iraq.

Outlining the coalition's strategy, the prime minister said: "First, we stand firm. We will do what it takes to win this struggle.

"We will not back down in the face of attacks either on us or on defenceless civilians."

'Opportunity'

Mr Blair put up a united public front on Iraq and Israel, despite pressure from some members of his Labour Party, including former Foreign Secretary Robin Cook, to take the opportunity to differ with the White House.

He insisted Ariel Sharon's plan did not "push aside" the internationally-agreed road map for peace, as some feared.

"What it does give us is at least the possibility of moving it forward," he said.

He urged the international community to "get involved" with the plan.

"Let's not look this opportunity in the eye and turn away," he told reporters.

Caretaker government

The summit has coincided with indications from senior US officials that they are prepared to accept a plan prepared by UN special envoy Lakhdar Brahimi.

It proposes replacing the US-appointed Iraqi Governing Council by a caretaker government after the 30 June handover.

The US has indicated that it is prepared to accept Mr Brahimi's proposals, which envisage the replacement of the US-appointed Governing Council by a new transitional authority that would run Iraq until elections could be held.